J/ApJ/962/100 ACO 746 analysis with Subaru & MMT spectra data (HyeongHan+, 2024)
Weak-lensing analysis of the complex cluster merger A746 with Subaru/Hyper
Suprime-Cam.
HyeongHan K., Cho H., Jee M.J., Wittman D., Cha S., Lee W., Finner K.,
Rajpurohit K., Bruggen M., Forman W., Jones C., van Weeren R., Botteon A.,
Lovisari L., Stroe A., Dominguez-Fernandez P., O'Sullivan E., Vrtilek J.
<Astrophys. J., 962, 100 (2024)>
=2024ApJ...962..100H 2024ApJ...962..100H
ADC_Keywords: Clusters, galaxy; Redshifts; Galaxies, spectra; Optical;
Gravitational lensing
Keywords: Abell clusters ; Galaxy clusters ; Weak gravitational lensing
Abstract:
The galaxy cluster A746 (z=0.214), featuring a double radio relic
system, two isolated radio relics, a possible radio halo, disturbed
V-shaped X-ray emission, and intricate galaxy distributions, is a
unique and complex merging system. We present a weak-lensing analysis
of A746 based on wide-field imaging data from Subaru/Hyper Suprime-Cam
observations. The mass distribution is characterized by a main peak,
which coincides with the center of the X-ray emission. At this main
peak, we detect two extensions toward the north and west tracing the
cluster galaxy and X-ray distributions. Despite the ongoing merger,
our estimate of the A746 global mass M500=4.4±1.0x1014M☉
is consistent with the previous results from Sunyaev-Zel'dovich and
X-ray observations. We conclude that reconciling the distributions of
mass, galaxies, and intracluster medium with the double radio relic
system and other radio features remains challenging.
Description:
We observed A746 with the Subaru HSC on 2023 January 16, 20, and 22
(PI: H. Cho). The total integrations are 3480 and 4320s in the HSC-g
and HSC-r2 bands, respectively, which cover ∼2.4deg2.
Spectroscopic observations (PI: K. Finner) were conducted with
Hectospec, a multi-object fiber spectrograph at the MMT Observatory.
We selected spectroscopic targets for A746 within the 1° diameter
field of view of the Hectospec instrument based on archival imaging
from Subaru/Suprime-Cam and SDSS and photometric redshift data.
The MMT/Hectospec observations provided a total of 244 spectra.
We successfully obtained reliable redshifts for 229 objects.
In addition to our MMT/Hectospec data, we compiled archival
spectroscopic data from Keck/DEIMOS (Golovich+ 2019, J/ApJS/240/39),
SDSS DR18 (Almeida+ 2023ApJS..267...44A 2023ApJS..267...44A), and NED.
Objects:
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RA (ICRS) DE Designation(s)
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09 09 34.76 +51 32 56.1 A746 = ACO 746
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 70 375 Spectroscopic redshift catalog of galaxies in the
A746 field
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See also:
V/154 : Sloan Digital Sky Surveys (SDSS), Release 16 (DR16) (Ahumada+, 2020)
J/ApJ/805/143 : MC2: redshift analysis of CIZA J2242.8+5301 (Dawson+, 2015)
J/A+A/594/A27 : Planck Sunyaev-Zeldovich sources (PSZ2) (Planck+, 2016)
J/ApJ/838/110 : Spectroscopic survey of ZwCl 0008.8+5215 (Golovich+, 2017)
J/ApJS/240/39 : Merging galaxy cluster deep observations (Golovich+, 2019)
J/ApJ/882/69 : Radio relic merging cluster substructures (Golovich+, 2019)
J/A+A/660/A78 : LoTSS-DR2 sample overview release (Botteon+, 2022)
J/ApJ/925/68 : Spectroscopic redshift catalog of the A1240 field (Cho+, 2022)
J/ApJS/258/11 : The COSMOS2020 catalog (Weaver+, 2022)
J/A+A/680/A31 : Radio relics in LoTSS-DR2 and PSZ2 (Jones+, 2023)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 12 F12.8 deg RAdeg [136.6/138.2] Right Ascension (J2000)
14- 24 F11.8 deg DEdeg [51/52.1] Declination (J2000)
26- 31 I6 km/s cz [-161/726603] Redshift velocity
33- 35 I3 km/s e_cz [0/120]? 1-sigma uncertainty on cz
37- 46 F10.7 --- z [-0.00054/2.43] Redshift
48- 58 E11.5 --- e_z [1.37e-06/0.00041]? 1-sigma uncertainty on z
60- 63 F4.1 --- RXC [2.5/31.3]? Cross-correlation score r-value (1)
65- 68 A4 --- Cat Catalog source code of spectroscopic data (2)
70 I1 --- Mm [0/1] Cluster membership (1=cluster member,
105 occurrences; see Section 2.4)
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Note (1): The cross-correlation score r-values obtained from IRAF/RVSAO are
valid only for the MMT data. We adopted a cross-correlation score
r-value (Tonry & Davis 1979AJ.....84.1511T 1979AJ.....84.1511T) RXC, a measure of the
significance of the cross-correlation peak, greater than 4 as secure
redshift measurements.
Note (2): The catalog source codes are the following:
MMT = our MMT/Hectospec observations (243 occurrences)
G19 = Golovich+ 2019, J/ApJS/240/39 (94 occurrences)
SDSS = SDSS DR18 (37 occurrences)
NED = NASA/IPAC Extragalactic Database (1 occurrence)
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History:
From electronic version of the journal
License: CC-BY-4.0
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 05-May-2026